What activation method triggers all audio/visual devices when a fire is detected?

The method that triggers all audio/visual devices when a fire is detected is the general alarm. This system is designed to alert building occupants and emergency personnel throughout the entire facility by activating all available notification appliances such as alarms, strobe lights, and speakers. The general alarm is crucial in scenarios where immediate evacuation is necessary, ensuring that everyone is made aware of the fire emergency promptly.

In contrast, a selective alarm may only activate devices in specific zones or areas of the building, which could delay a full-scale evacuation if occupants in other sections are not alerted. A manual alarm typically relies on human intervention to activate the devices, which may not provide rapid notifications when time is of the essence. Lastly, a local alarm is usually limited to a specific area and may not connect to a broader network of notification devices, potentially leaving other areas uninformed. Thus, the general alarm is the most comprehensive method for ensuring that all individuals in a building are alerted in the event of a fire.